420 AMERICAN ANTHROPOLOGIST [n. s., I, 1899
The sum of experience concerning the blending of human blood is easily stated. No tribes, or races, or nations are drifting apart in blood, none have drifted apart (if such a process be pos- sible) during any period recorded in history, while all are now either running parallel or converging and uniting — in other words, the blood distinction of the world is steadily diminishing, and is less today than ever before since the beginning of history or in- terpretable prehistoric record.
The prominent facts of cranial size and structure revealed in the pithecanthropoid and higher types, and the hardly less con- spicuous fact of reshapement of hands and other organs through exercise in the essentially human activities, shed some light on the features and functions of the human prototype, and so on the earliest steps of human progress, the testimony of Pithecanthro- pus being peculiarly significant. Viewed collectively, the great facts seem to indicate that the transformation began with the assumption of the erect attitude, and advanced with cumulative rapidity as the processes of cephalization and cheirization went forward. Now, the erect attitude itself suggests maturing differ- entiation between the locomotor and prehensile organs, coupled with definite concentration of function in the two pairs of differen- tiated limbs ; while the skull-molding and hand-shaping activities necessarily attending the erect attitude betoken a degree of anterior development hardly consistent with the retention of diverse posterior organs for locomotion and prehension combined (indeed the human body is characterized by relative smallness of the lumbar ganglionic complex, scarcely less than by relative largeness of the brain-case) ; so that the several lines of structural facts seem to point to a tailless ancestry, not merely at the critical stage but throughout eons of antecedent progress. These phylogenetic indications emphasize the obvious outward differ- ences between existing quadrumanes and men, and at the same time explain the absence of living links between the simian or
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